The apparent lack of meaning of an abstract form, like a circumference, is nothing more than a sign indicating something, a signal of space and time: someone has done it in a place at a certain time. This sign is a warning of the passage of a person who leaves a self-referential message, but which does not leave the observer indifferent. It is a sign loaded with questions, but which works ephemerally on a territory and then blends in it. The wind blows, and the dust will fly again to join a new reality.